High-frequency apparatus



Y Oct-1,1946. 1 I w H. BENVIOFF 2 8,

HIGH FREQUENCY APPARATUS Filed July 10, 1942 INVENTOR BY Hucso BENIOFF (WM M ATTORNEY Patented Oct. 1, 1946 UNITED STATES PATENT OFFICE 2,408,407" HIGH-FREQUENCY APPARATUS fiugo .Benioff, Ila-Canada,'. Caiif., assignor, by. mesne assignments, to Submarine Signal Com pany, Boston, Mass, a corporation of Delaware ApplicationJuly 10, 1942-, Serial No. 450,451 1 1. The present invention relates to apparatus for producing ultra high-frequency electromagnetic waves and relates-more particularly to short-wave radio transmitters in a frequency range of 150 inegacycles and higher.

The present invention is an improvement-oi my copending 7 applications Serial No. 362,434, filed October 2 3-,l940,- serial;No. 391,153, filed April 30,

1 941,} and Serial. No;1432,293, filed February 25, 1942; In thelast oi-theseapplications a spark; tank circuit is shown in whic there is used two closelyspaced plates with thesparking electrodescentrally located therein.

The present invention relatesto thesame gen- 9 oral apparatus and finds its chief improvement and advantage in that a greater'amount of powercan be more'readily handled "than 'in the .former' embodiment. In the present application a direct current polarizing voltage is employed which, it

appears, prevents a premature discharge across the sparking electrodes and permits the voltage.

between, plates to rise to a higher value before breakdown of the gapwith a resulting storage of increased amount of energyfor liberation during the discharge of the gap.. l The presentinvention is "further simplified in that in this form it is unnecessary to provide aux-.

iliary sparking electrodes. r 7

' A further advantage obtained in the present invention is that the resonant oscillatory circuit is coupled more efficiently to the radiator and that the radiator functionsmore efficientlyin the radiationof electromagnetic power.

, The applicant believes, but he is not certain,-

from studies and tests of-the present invention that after the discharge across thespark gap, the

oscillatorycircuit establishes itself with the op--- posed plates as a capacity and-the radiators extending therefrom as resonant quarter wave length elements forming a one-half wave length radiating system. 7 V

, Other constructional features and advantages .11 Claims.

will be morefully appreciated and understood."

from the description contained in the specifica-- tion below when taken in connection with the drawing 'in which Fig. 1 shows a central section through the apparatus and the operating wiring diagram connected therewith, and Fig. 2 showsan end View. of the apparatus shown in Fig.1.

In'Figl the apparatuscomprises .two opposed conductive plate members I and 2 with centrally. located electrodes preferably of tungsten or other suitable material 3 and imounted and projecting I from the opposing suriacesi'ofthe plates I and 2 with the points of the electrodes in actual alignisrcentrally spaced between the innersurfaces of the plates I and 2, has .a'centrallylocated perfo-. ration I3 into which the points-of the electrodes 3' and 4 may slightly project; The plates l and .2 may be mounted and held tofthe mica discs 5 and. 6 by means of suitable shortscrews I4, 14' and. I 5, I5, although any other suitable means for at taching the plates tothediscsv 5 and 6 may be employed. The plates I and 2 make good electrical contact with rearwardly projecting members (I and I8 which maybe formedas a part of the. conductingcylindersv I9 .and 20, respectively. The- -elements I1 and I8 are also of highly conductive material. .Thewhole system, comprising the cylinders I9 and 29, theconnecting elements ll and I8, the plates I and 2 withtheir projecting electrodes 3 and 4, forms both the spark tank circuitl and the radiating circuit. I I Within'the cylinders I9 and 20, respectively, are. telescopic cylindrical elements I9 and 20' which, may be extended beyond theledge of the. cylinders-I I 9 and 20 to increase the efifective antenna length;

. and adjust for tuning of the system; These.tele-' scopic cylinders. I 9 and 20"maybe omitted where. the antenna length is definitelydetermined and. no tuning adjustment is required.

Initially the voltage is built up between the plates l and 2 until a breakdown occurs in the region between the electrodes 3 and 4 and the perforation I3 in the disc l2. The electrodes are spaced apart a distance determined by the maximum available potential atbreakdown. As an.

illustration in one case with breakdown occurring.

with 21,000 volts between plates, the spacing was .050 of an inch for the point electrodes. Before.

the breakdownoccursthe. energy is storedup in' the tank circuit with extreme stresses occurring between the plates I and 2. Breakdown of the spark releases energy stored in the-capacity of the tank circuit and sets up oscillations. in the I tank circuit which is coupled with the antenna,

thus providing means for radiating power.

Under normal conditions there is present. in. the gap enough ions to bring about a breakdown between the sparking electrodes 3 and 4 at relatively low voltages. By the use of a direct current polarizing voltage the free ions remaining in the gap after discharge are cleaned out, thus increasing the potential at which discharge oc- 5 curs. This polarizing potential must be direct current or timed low frequency pulses of a sufficient value.to effect the desiredcleaning .out, of the space .betweemtheelectrodes: Wherethe impulse potential is built up to a peak in the higher than that which could normallyjbemaine- 151,-

tained may be reached betweemjheel'ectrodesbefore a breakdown occurs. The mica disc l2 which is centrally located between plates l' and =2 prevents breakdown at points other .thansthe.

gap in the space between. the plates due to stray ion not. removed by the direct current potential; ThB.thlGkIiESS"Of the micaplate shouldpreferably be small compared to the spacing betweerr platesr The circuit for .operatingtheioscillator' includes an impulse transformer T1; the *primary'of which is'energizedby a. gaseous"tube""2l*wh'ich has a cathode, anode and control electrode. A trigger ing'impulse maybe impressed between the oathode'and the control electrode in'a manner similar. to that described 'inrmy copen'ding': applicatiomSerial 'N'o; 432,293referredto above. The condenserxCiis charged'from a source 22 through a'resis'tor R1 when the thyratrontif is in 'a'noncondu'ctingtconditiont When the gaseousptube 21 'isxendered conduct'rng'b'y the-action of the triggeripulse'on'its grid; the :ch'arge'on' C'z passes through 'theprimarywf the transformerTi in the form; of ash'ortipulse: The output of the secondary is impressed 'upon the plates of'the 40 tank'circui't. Theconstants'of thecircuit are so chosen as to charge the plates-in a.few. microe seconds; Chokeslalaarmefiective. at the 'oscil-' lator frequency" (which may,;. for "instance; be 600"megacycles)'. ductan'cerandi are effective at charging impulse; frequencies. In order-.to be. effective .at ultra high" frequencies the windings of "L2 are wound of. very fine wire on a core;.of smallldia'meter; and

with appreciably spacedfiturns'. There is als'oin the. circuitlwith" the itransforrrrei a condenser '03 acrossithe terminals ofjwhich the'direct polarizing Tvoltage '24""is applied." This "polarizing-voltage is applied through a high resistance The source 24 maybe applied throughthe whole period ot'operationasidesiredxand the impulse voltage generated-by" the -transformer Ti willbe superimposed upon this polarizing voltage during the charge of'thetank circuit. The action of the polarizing voltage is suchiithat 'upon dis charge'zof the tankcircuit a normal uniform voltage isquicklyiprovided across'the' space between the' plates, thus causin'g the positive ions remaining in" the'space to travel to" the negative plate 'and'the negative ions to travel 110 the .posi-' tiveplate. Thi red'ucesthe. number :of' ionsgi'n this space;

Havingnow describedjmyinvention, I claim:

I; In an..ultra.short wave oscillatory spark cir-- cuit,. in .combination,. twoi flatplates spaced with.

their .tacesurfaces in closely... opposed. relation.- ship,,with each. other, electrodescentr'ally. positioned in opposing. .relati'onship on saidplates. and facing each other, means insulatingly-supportingjsaid platesin sai'd'position. and an i ulat Chokes'23. are oijhigher in- 4 ing sheet positioned midway between the faces of said two plates, said insulating sheet having a perforation in alignment with said electrodes.

2. In an ultra short wave oscillatory spark circuit, in combination, two flat plates spaced with their face surfaces in closely opposed relationship with each other, electrodes centrally positioned in opposing relationship .on said plates and-facing Ieachrother, means comprising insulating discs attached to the backs of said plates, an insulating sheet positioned midway between the faces of said two plates, said insulating sheet having. aperforation in alignment with said electrodesand means supporting said insulating discs and sheetsin para-Her positions with each other.

3'..An.ultra.-sliort. wave oscillatory spark circuit comprising-two flat plates spaced with their facesurfacesirrc-losely opposed relationship with each other, electrodes centrally positioned in opposing relationship on said plates and facing each other, means insulatingly supporting said plates in'said'position' and'acondncti-ng'shell supported to the back of each of said plates iii-conducting relationship therewith; said conducting shell hav-' ing a longitudinal dimension adjusted for the desired resonance in the oscillator-circuit.

4'; In an ultra short waveoscillatory spark circuit; in'combination two flat plates spacedwiththeir face-surfaces in closely opposed relationship w-ith-eacli other, electrodescentrally positibned in opposing relationship on said plates and facing each' other, means insulatingly supporting said plates in said-position; an insulating" sheet positioned midway betweenthe faces of saidtLtwo-plates; said insulating sheet having a perforationin alignment with said electrodes, and means providing a direct'current potential between said'plates for sweepingout the free ions' to prevent apremature discharge between said electrodes.

51 In an ultra shortwave 'oscillatory'spark cire cuit, in' combination, two flat'plates spaced with. theirface surfaces in closelyopposed relationship with eaclr other, electrodes centrally positioned. in" opposin rela'tionshipon said plates and facing each other, means insulatingly supporting said plates in said position and: means providing. adi'rect current potential between said: plates for. removing ions to prevent apremature discharge between said electrodes;

6.-'-'An ultra shortwaveoscillatory spark circuit-comprisingtwo-fiat plates spaced witl'rtheir. face-surfaces-irrcloselyopposed relationship with each other, electrodes centrally positioned in opposing relationship on said plates and facing. eachother; means 'insulatingly supporting said. plates in 'sai'dposition, a conducting shell supported tothe back of each'of' said plates in conducirig' relationship therewith, said conducting shell having a longitudinal dimension adjusted forithe desired resonance in the oscillator circuit, and means providing a direct current potentialabetween said plates for sweeping out the free ions after'a discharge has-occurred between said. electrodes.

7. An ultra short wave oscillatory spark circuit comprising two'flat' plates spaced with their face; surfaces-in closely opposed relationship with each' other; electrodes centrally'positionedin"op= posing relationship on" said "plates and facing each other; means insulatinglY. supporting said plates in" said position, .a conducting: shell sup; ported to the backof each of saidplates in conducting elationship therewith, said conducting; shell 'having 'alongitudinal" dimension adjusted for the desired resonance in the oscillator circuit, said conducting shell having a diameter substantially as large as the diameter of said plates.

8. An ultra short wave oscillatory'spark circuit comprising two flat plates spaced with their face surfaces in closely opposed relationship with each other, electrodes centrally positioned in opposing relationship on said plates and facing each other, means insulatingly supporting said plates in said position and a conducting shell supported to the back of each of said plates in conducting relationship therewith, said conducting shell having a longitudinal dimension adjusted for the having a perforation in alignment withsaid electrodes. Y I

, 10. An ultra short wave oscillatory spark circuit comprising elements providing two closely spaced surfaces in opposed relation to each other, electrodes centrally located on and projecting towards one another from said surfaces, means in- I sulatingly supporting said elements in said posidesired resonance in the oscillator circuit, said conducting shell having a diameter substantially as large as the diameter of said plates, said shell being supported to said plates at the central sec- 'tion and a conducting shell supported to the back of each of said elements in conducting relationship'therewith, said conducting shell having a longitudinal dimension adjusted for the desired resonance in the oscillatory circuit.

11. An ultra short wave oscillatory spark circuit comprising elements providing two closely spaced surfaces in opposed relation to each other, electrodes centrally located on and projecting towards one another from said surfaces, means insulatingly supporting said elements in said position and a conducting shell supported to the back of each of said elements in conducting relationship therewith, said conducting shell having a longitudinal dimension adjusted for the desired resonance in the oscillator circuit, said shell having a diameter of substantially the same size as said elements. v v

HUGO BENIOFF. 

